Keep the printed quantity kind
No universal conversion is established here. Litres describe volume;kilograms describe mass. Granule size,material and packing can differ among products. All three selected offers publish litres in the reviewed listings,so the tools support declared-litre cost while withholding a per-kilogram result.
Do not borrow another product’s density
A different bag labelled 10 L and a separately stated mass does not supply a density for this selected 10 L wood offer. Nor does a 20 L bag necessarily weigh twice a 10 L bag of another material. We have not weighed contents or measured loose and compacted bulk densities.
Compare only a supported denominator
If a future product supplies only kilograms,compare it on that declared mass basis with other supported mass offers. Do not put its numerical quantity into the litre field to produce an apparently tidy price ranking. A common number is not a common unit.
Choose the next evidence request
For carrying,delivery limits or a storage load question,request the exact filled-package or net-mass specification you actually need. A declared capacity cannot establish either by itself. Unknown weight is a practical limitation of this shortlist,not an invitation to estimate it from a product photograph.
Apply the distinction to a purchase
If a 20 kg alternative is later added,it needs its own price-per-kilogram line. Without a verified conversion,the two unit families can be displayed side by side but cannot form one numerical cheapest-per-unit ranking.
Sources & scope
Checked November 5, 2026. Manufacturer and retailer references support the specific statements. Dated displayed prices are not final checkout quotes, performance rankings or performance testing. This shopping reference does not replace the exact product label or retailer instructions. Current received labels and independent veterinary/material/content/commerce review remain pending.
Tesco UK Catsan Hygiene20L product260814123 ↗